On 8/7/21 6:18 AM, Damien Le Moal wrote:
Avoid static checkers warnings about a potential NULL pointer
dereference for the port info variable pi. To do so, test that at least
one port info is available on entry to ata_host_alloc_pinfo() and start
the ata port initialization for loop with pi initialized to a non-NULL
pointer. Within the for loop, get the next port info (if it is not NULL)
after initializing the ata port using the previous port info.
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Signed-off-by: Damien Le Moal <damien.lemoal@xxxxxxx>
---
drivers/ata/libata-core.c | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 61c762961ca8..b17e161c07e2 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -5441,16 +5441,17 @@ struct ata_host *ata_host_alloc_pinfo(struct device *dev,
struct ata_host *host;
int i, j;
+ /* We must have at least one port info */
+ if (!ppi[0])
+ return NULL;
+
host = ata_host_alloc(dev, n_ports);
if (!host)
return NULL;
- for (i = 0, j = 0, pi = NULL; i < host->n_ports; i++) {
+ for (i = 0, j = 0, pi = ppi[0]; i < host->n_ports; i++) {
struct ata_port *ap = host->ports[i];
- if (ppi[j])
- pi = ppi[j++];
-
ap->pio_mask = pi->pio_mask;
ap->mwdma_mask = pi->mwdma_mask;
ap->udma_mask = pi->udma_mask;
@@ -5458,8 +5459,13 @@ struct ata_host *ata_host_alloc_pinfo(struct device *dev,
ap->link.flags |= pi->link_flags;
ap->ops = pi->port_ops;
- if (!host->ops && (pi->port_ops != &ata_dummy_port_ops))
+ if (!host->ops && pi->port_ops != &ata_dummy_port_ops)
host->ops = pi->port_ops;
+
+ if (ppi[j + 1]) {
+ j++;
+ pi = ppi[j];
+ }
}
return host;
This requires a comment as to why this is necessary.
Cheers,
Hannes
--
Dr. Hannes Reinecke Kernel Storage Architect
hare@xxxxxxx +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Felix Imendörffer
